1. Field of the Invention
The present invention relates to a pavement marker which is used for allowing a median strip of a roadway to be easily discerned in the nighttime, and more particularly, the present invention relates to a pavement marker which is constructed in such a way as to maximize a light emissivity and improve a strength, and a method for manufacturing the same.
2. Background of the Related Art
Generally, a pavement marker is embedded, on a median strip, into the ground. Light emitting lamps are arranged in the pavement marker, and reflective plates are respectively attached to both side surfaces of the pavement marker, in a manner such that lights are emitted through the reflective plates. In this way, the pavement marker serves as auxiliary means for allowing a driver to easily discern the median strip while driving at the nighttime.
Such a pavement marker uses as its power source solar energy. That is to say, solar energy absorbed by solar cells in the daytime is converted into electric energy. Electric energy is then stored in a rechargeable battery to be used in the nighttime. Thus, the pavement marker can emit lights by itself without any separate power supply.
The conventional pavement marker constructed as mentioned above suffers from defects in that, since the pavement marker projects upward from a surface of a roadway, it repeatedly receives loads by automobile tires. Thereby, the reflective plates exposed to the outside are likely to be broken, and a possibility of an electric circuit including the solar cells to be damaged is increased.
Accordingly, in spite of a reduced installation cost and acceptable discernability when compared to other kinds of pavement markers, due to the breakage or damage, limitations are imposed on the extensive use of the above-described kind of pavement marker, through an extended period of time.
Also, the reflective plates respectively attached to both side surfaces of the pavement marker to allow passage of lights therethrough can be stained with dirt or filth existing on the roadway, or a light emissivity through the reflective plates can be deteriorated under bad weather accompanied with rain, snow or fog, whereby discernability and a field of view of a driver can be abruptly degraded.
Moreover, the degradation in discernability and field of view can result in a traffic accident, and, thereby, a loss of manpower and material resources can be caused.
Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a pavement marker in which light emitting lamps are installed in such a way as to horizontally project from a solar cell assembly, and the solar cell assembly has formed therein epoxy layers, whereby a light emissivity through reflective plates respectively attached to both side surfaces of the pavement marker is maximized and a strength of the pavement marker is improved; and a method for manufacturing the same.
Another object of the present invention is to provide a pavement marker in which a packing member is fitted into a packing member fitting groove defined on a lower surface of a transparent resin block, whereby moisture contained in the ground is prevented from leaking into a solar cell assembly, and thereby waterproofness is accomplished.
In order to achieve the above objects, according to one aspect of the present invention, there is provided a pavement marker in which a solar cell assembly is arranged between an upper case defined through its upper wall with a sunlight opening and a lower cover formed on its lower surface with a stem portion, the solar cell assembly having solar cells and light emitting lamps, and reflective plates are respectively attached to both side surfaces of the upper case, wherein the solar cell assembly includes a transparent resin block having an upper wall, support protrusions are formed on an inner surface of the upper wall of the transparent resin block, and a solar cell set having the solar cells and a printed circuit board is disposed in the transparent resin block in such a way as to be brought into contact with the support protrusions; wherein a plurality of airtight bosses are horizontally and projectedly formed on both side surfaces of the transparent resin block, a plurality of lead wire insertion holes are defined through both side walls of the transparent resin block in the plurality of airtight bosses, respectively, and the light emitting lamps are respectively fitted into the airtight bosses and electrically connected with the solar cell set through the lead wire insertion holes, with only base portions of the light emitting lamps received in the airtight bosses and body portions of the light emitting lamps projecting out of the airtight bosses; and wherein epoxy layers are formed inside the transparent resin block in a manner such that the solar cell set is sandwiched between the epoxy layers, the lead wire insertion holes are sealed and the light emitting lamps are firmly fixed with respect to the airtight bosses.
According to another aspect of the present invention, the transparent resin block is defined on a lower surface thereof with a packing member fitting groove, and a packing member is fitted into the packing member fitting groove so that waterproofness is ensured between the lower surface of the transparent resin block and an upper surface of the lower cover.
According to still another aspect of the present invention, there is provided a method for manufacturing a pavement marker in which a solar cell assembly is arranged between an upper case defined through its upper wall with a sunlight opening and a lower cover formed on its lower surface with a stem portion, the solar cell assembly having solar cells and light emitting lamps, and reflective plates are respectively attached to both side surfaces of the upper case, the method comprising: a first step of defining an accommodating space in a transparent resin block made of transparent resin, in a manner such that a lower end of the accommodating space is opened and a solar cell set which has the solar cells and a printed circuit board bonded with each other can be accommodated in the accommodating space, forming support protrusions on an inner surface of an upper wall of the transparent resin block, and forming airtight bosses on both side surfaces of the transparent resin block and defining lead wire insertion holes through both side walls of the transparent resin block in the airtight bosses, in a manner such that the light emitting lamps can be horizontally fitted into the airtight bosses, respectively; a second step of disposing the solar cell set in the accommodating space defined in the first step, in a manner such that the solar cell set is brought into contact with the support protrusions, fitting the light emitting lamps into the airtight bosses in a manner such that only base portions of the light emitting lamps are received in the airtight bosses and body portions of the light emitting lamps project out of the airtight bosses, and electrically connecting the light emitting lamps with the solar cell set through the lead wire insertion holes; a third step of injecting a predetermined amount of epoxy resin into the accommodating space defined in the transparent resin block in a manner such that the solar cell set disposed in the second step is encapsulated by the epoxy resin; a fourth step of forming epoxy layers inside the transparent resin block by discharging air for 30 minutes at 1 atmospheric pressure using a vacuum tank, in a manner such that the epoxy resin injected in the third step fills the accommodating space, the lead wire insertion holes, and clearances defined between the base portions of the light emitting lamps and the airtight bosses, and air contained in the epoxy resin is removed; and a fifth step of thermally setting at 70xc2x0 C. for 30 minutes the epoxy layers formed by the epoxy resin, after air is discharged in the fourth step, in a manner such that the solar cell set is sandwiched between the epoxy layers inside the transparent resin block and the light emitting lamps are firmly fixed with respect to the airtight bosses.